ADLINK CoreExpress-ECO2 - Manual (Page 16)

4.7 Read Ontime Seconds
This command reads the Ontime Seconds of the System running in S0-State starting at last power-
on. The Ontime Seconds-counter has a 32-bit (four byte wide) size and is count-up every second in
the SMC. The counter is cleared when the system is removed from power. The Most Significant Byte
is sent first, followed by the next highest Byte down to the Least Significant Byte (Table 4.7.1).
START SMC_addr ACK command ACK START (Repeat) SMC_addr+1 ACK
length ACK(C) Byte 1 (MSB) ACK(C) … ACK(C) Byte 4 (LSB) ACK(C) STOP
Table 4.7.1 SMC transmitter format of the Ontime Seconds Command Code
ITEM DESCRIPTION
START SM-bus start condition
SMC_addr 0x50 (8-bit)
ACK SM-bus acknowledge condition generated by receiver
command 0x33 = “Read Ontime Seconds” Command code
Length 0x04 = 4 Bytes data length
Byte 1-4 Value of Ontime Seconds Counter
STOP SM-bus stop condition
Table 4.7.2 Explanation of Table 4.7.1